Cedergren was a Swedish

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 telecommunications company running the telephone network in Warsaw

Warsaw

Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...

 between 1900 and the interbellum. Named after its founder, Henrik Tore Cedergren, it was notable as the first official phone operator in that city and the company to finance the Cedergren building

PAST

PAST was a Polish telephone operator in the period between World War I and World War II. It is notable for its main headquarters in Warsaw, which at the time of its construction was the first and tallest skyscraper in the Russian Empire and the tallest building of Warsaw...

, the first skyscraper in the then Imperial Russia. Its assets in Poland were taken by its successor, the PAST

PAST

PAST was a Polish telephone operator in the period between World War I and World War II. It is notable for its main headquarters in Warsaw, which at the time of its construction was the first and tallest skyscraper in the Russian Empire and the tallest building of Warsaw...

 company, when the license expired in the 1922. The Swedish branch of the firm were bought by Almanna Telefon AB LM Ericsson, the predecessor of modern Ericsson

Ericsson

Ericsson , one of Sweden's largest companies, is a provider of telecommunication and data communication systems, and related services, covering a range of technologies, including especially mobile networks...

company http://www.ericsson.com/pl/ericsson/ericsson_w_polsce.shtml.